Liquid-solid interfaces (LSI) simulations are
performed for the purpose of determining the melting line by the
two-phase coexistence. The procedure follows the approaches proposed
in Refs. [1]}, [2]}, [3]}, [4]}, [5]}, [6]}, [7]}, [8]}, [9]} and is similar to the
protocol used in Ref. [10]}. A simulation cell containing
around \(N=43000\)  atoms was set up with an initial crystalline
configuration with shape \(28\times 7\times 7\)  primitive cells on which
PBC applied to the three directions of space. Starting at zero
pressure, this system is heated and equilibrated at constant pressure
to a temperature of 50 K below a guess of the melting temperatures.
Half of the simulation cell in the \(x\)  direction is further heated
and maintained at a temperature of approximately 1300 K until a
complete melting is observed. The liquid part was then cooled down
and equilibrated at a temperature 50 K above the guess, thus
creating a solid-liquid coexistence containing two crystal-melt
interfaces due to the PBC. The simulation of the entire system is
pursued in the isobaric-isoenthalpic ensemble so that the temperature
of the LSI is an internal parameter free to evolve toward a steady
state corresponding to the thermodynamic melting temperature if
both phases survive. The simulation is continued for 1 ns, and
the average melting temperature is determined on the last 100 ps
when a steady position of the two interfaces is observed. If a
complete melting or solidification occurs, the procedure is started
over again with a refined guess of the melting temperature. This
procedure is repeated with subsequent higher pressures by first
shrinking the volume of the whole simulation cell from the coexistence
configuration at the preceding pressure and then increasing the
temperature at constant pressure to a new guess of the melting line.
